The present invention relates generally to an apparatus and method for setting welding run-off tabs in a coil end joiner. More particularly, the present invention relates to an apparatus and method for setting welding run-off tabs in a coil end joiner which facilitates the positioning of and retains welding run-off tabs in position to provide full edge-to-edge weld penetration in a coil end to coil end weld joint.
In many metalworking operations involving stamping, forming or otherwise processing e metallic material provided in a coil configuration, it is desirable to join the trailing end of a coil about to be depleted with the leading end of a new coil to facilitate the manufacturing operations. For example, if coil material is being fed through a press or some other piece of metalworking equipment, it is often desirable to have an "endless" supply of material to reduce or eliminate the necessity of "rethreading" the coil material when a coil is depleted. In the past, various types of coil end joiners have been used to join the trailing end of a coil about to be depleted with the leading end of a new coil to provide such an "endless" supply of material.
However, many prior art coil end joiners have simply butted up the trailing end of a coil about to be depleted with the leading end of a new coil and have joined the two (2) pieces together, typically using an arc welding process, such as gas tungsten arc welding (GTAW), or perhaps more commonly known as tungsten insert gas (TIG) welding. As seen in FIG. 1, while such a coil end weld joint provides a good weld joint in the central portion of the joined coil ends, either an unwelded edge area, or even more negatively, a semi-circular "blowout" area or cutting-out of the coil end weld joint typically occurs at both the initial side and the terminal side of the weld joint.
While a partial width, not a full edge-to-edge, coil end weld joint could be tolerated in some metalworking operations, other metalworking operations either require or would benefit from full edge-to-edge integrity of the coil end weld joint. For example, a trend in many metalworking operations is to strive to utilize a greater percentage of the raw material in end products and reduce the remaining "skeleton" web of scrap metal as much as possible. Thus, many stamping operations, such as the stamping of motor laminations, utilize either the entire width or substantially the entire width of the coil to fabricate the end product. If such a product is stamped across a coil end weld joint having a semi-circular "blowout" area or cutting-out of the coil end weld joint on either side of the coil, the end product would be defective and, perhaps in most cases, would have to be scrapped. Further, in other metalworking forming operations, such as forming a coil material into an end product having a tubular configuration, all of the coil material is utilized in the end product. Thus, an end product fabricated with a coil end weld joint having a semi-circular "blowout" area or cutting-out of the coil end weld joint would be defective and, in most cases, would have to be scrapped. Furthermore, in some metalworking operations, it is necessary or desirable to maintain a continuous "skeleton" web to, for example, provide for continuous "pull-through" of the "skeleton" web.
In addition to the semi-circular "blowout" area or cutting-out of the weld joint which sometimes occurs at both the initial side and the terminal side of the coil end weld joint, a significant build-up of metallic material typically occurs at the initial side of the weld joint. Such a build-up of metallic material can have a negative effect on subsequent feeding, machining, tooling and/or other manufacturing operations and, if nothing else, is unsightly in a final end product and may necessitate further end product rework and/or repair operations.
In order to provide a full edge-to-edge coil end weld joint, welding run-off tabs, typically fabricated from a material having a composition and a thickness comparable to that of the coil material, have been manually placed on both the initial and the terminal side of the coil end weld joint. Such welding run-off tabs permit the welding arc to begin on the initial welding run-off tab, continue across the coil end weld joint into the terminal welding run-off tab and be extinguished on the terminal welding run-off tab. As seen in FIG. 2, the use of such welding run-off tabs provides a coil weld joint which extends completely from the initial side to the terminal side of the coil end weld joint with no significant semi-circular "blowout" area or cutting-out of the coil end weld joint occurring either at the initial side or the terminal side of the coil end weld joint. Once the coil end weld joint is completed, the welding run-off tabs are removed from the coil end weld joint. The welding run-off tabs can be snapped off by a gloved hand, or in some cases, by using a hand tool, such as a pair of pliers, and a coil end to coil end weld joint is provided having full edge-to-edge weld penetration.
In the past, welding run-off tabs have typically been manually placed on the initial side and the terminal side of the coil end weld joint. Such manual placement of welding run-off tabs takes a significant amount of time and, at the same time, does not always result in a good fit-up or placement of the welding run-off tabs in relation to the coil end weld joint.
Accordingly, an object of the present invention is the provision of an apparatus and method for setting welding run-off tabs in a coil end joiner which facilitates the placement and positioning of an initial welding run-off tab and/or a terminal welding run-off tab in a coil end joiner.
Another object of the present invention is to provide an apparatus and method for setting welding run-off tabs in a coil end joiner which retains an initial welding run-off tab and/or a terminal welding run-off tab in position in relation to a coil end weld joint until the coil end welding process is complete.
Yet another object of the present invention is to provide an apparatus and method for setting welding run-off tabs in a coil end joiner which is economical to fabricate, maintain and use.
These and other objects of the present invention are attained by the provision of an apparatus and method for setting welding run-off tabs in a coil end joiner which includes a support table having a U-channel therein, the U-channel having an opening through a base portion thereof, a left hold down clamp and a right hold down clamp positioned to either side of the U-channel over the support table, a first angled member having an actuator which provides horizontal movement of the first angled member, the first angled member extending upwardly through the opening in the base portion of the U-channel and contacting a corresponding second angled member such that horizontal movement of the first angled member results in vertical movement of the top surface of the second angled member which is parallel to the top surface of the support table. A rear welding run-off tab holder member having a U-channel therein is positioned over the second angled member and includes a rear welding run-off tab clamp which is positioned at a rear end thereof. A forward welding run-off tab holder and copper chill bar member includes a forward welding run-off tab clamp on a forward end thereof. The forward welding run-off tab holder and copper chill bar member is positioned in the U-channel in the rear welding run-off tab holder member. The apparatus and method for setting welding run-off tabs in a coil end welder facilitates the positioning of and retains a rear welding run-off tab and a forward welding run-off tab in position until the coil end welding operation is completed.
Other advantages and novel features of the present invention will become apparent in the following detailed description of the invention when considered in conjunction with the accompanying drawings.